In JSC what's currently working
In JSC what needs work
In Webkit browser package what's currently working
Gtk2 and Gtk3 bindings. Custom controls working independently of bindings. Some designers and component editors. A lot of functionality has been included beyond what was shown in the demo, including browser element hit testing, intercepting resources before they load, custom alert/confirm/prompt handling. Mostly documented.
In Webkit browser what needs work
Needs download manager code for handling what to do when links that want to download files. Cocoa/Carbon and Qt4/5 all have a paths forward and I have the sources ready. They use the same basic API so changes should be minimal and mostly related to WSClass details. Windows has not been researched yet, but should be possible. I need to implement a few more helper controls. Testing, demos, and videos. Synchronize changes from the JSC package into the Webkit browser package.
So in summary
I will finish the JSC package first, publish it, then do more work on the Webkit browser. The JSC package code is close to done, but demos will needs some time. Everything should work on all major platforms when complete and offer similar experiences.
Notes about Gtk
Continued Gtk2 support for Webkit was stopped a few years ago. It works, but there have been no updates by the Webkit team for a few years and there are some security holes that won't be patched. Also it does not have the same performance enhancements or improvements as the Gtk3/Mac/Qt versions. I have made some improvements to the LCL Gtk3 units which in order to better support Gtk3. I will publish those changes to Mantis as a patch when the Webkit web browser package is published.